It's not you. The Mangaka is bad at pacing. I know he/she wants to tell a story here but it constantly seems distracted by its own side stories and other mundane things that are of little interest to the reader. Also all the characters are a mystery, no questions were answered clearly to put...
Reread the manga, Masgrande. She starts dating an old man. Who do you think she is talking to when she's calling someone a "Pedo"?
What agreement is she referring to?
Plenty of clues in the setting as well.